How to make peeling edges of a paper
There are 2 main ways to curl a plane, using the SimpleDeform>Bend modifier, or using the Curve modifier with a curled curve object. I personally think the Curve solution is more accurate and controllable.


Create a curve with a long flat portion and curled portion at the end. 
Line the curve up diagonally with the plane so that the curl part of the curve is beyond the corner of the page
Add the Curve modifier to the page and select the curly curve object
You may need to reposition the page or the curl object to get them to line up properly.
Keyframe the position of the curve so that it moved diagonally across the corner of the page. As it does so the corner will curl up.
You will need the page mesh to be fairly subdivied, and may also need to add a subsurf modifier to smooth it out even more.